Drug therapy of Type II diabetes is positioned as a treatment for patients whose conditions are not sufficiently improved by dietary therapy or exercise therapy. Up to now, agents have been developed such as preparations with insulin that is an endogenous hormone controlling hypoglycemic actions, or oral hypoglycemic agents having actions such as insulin secretagogue action or peripheral insulin sensitizing action. At present, it is the mainstream method of drug therapy of Type II diabetes that blood glucose is precisely controlled by using oral hypoglycemic agents. However, in case that sufficient insulin actions cannot be obtained to improve hyperglycemia by using such agents, insulin therapy is applied as a main method. On the other hand, to Type I diabetes, administration of insulin therapy is the only treatment because such patients' insulin secretion ability is extinct.
Thus, though the insulin therapy is used as an important treatment method, there are problems such as procedure complication and need of patient education because it is injection solutions. Accordingly, improvement in the administration method is strongly desired from the aspect of improvement in compliance. Recent years, several insulin administration methods by various non-injection preparations to replace injection solutions have been developed and tried, but they are not led to practical use because of the problems such as the poor absorption efficiency and unstable absorption thereof.
As one of the main hypoglycemic actions of insulin, insulin has the action which increases the sugar-transporting capacity of peripheral cells, makes sugars in the blood take in the peripheral cells, and, as a result, lowers the blood glucose level. Thus, if new oral medicaments are found such as those lowering the blood glucose level by an effect of increasing the sugar-transporting capacity of peripheral cells, it is expected to become a promising treatment for diabetic diseases. For example, the compounds described in Patent Literature 1 are known.
[Patent Literature 1] WO 02/44180